MP3Tag version 2.55a
iTunes version
Windows 7 Pro 64bit SP1

Looking at the Tag field mappings,
there is a RELEASETIME (TDRL) tag.
However, RELEASETIME does not appear in the Tag Panel.

Mp3tag Options dialog | Tag Panel menu item | Add field ... button | Edit field ... dialog
The Field list does not have "Releasetime".

Thanks in advance.

I have the same question.
It is a confirmed and valid id3v2.4 tag field isn't it?

Sometimes the fieldlist is corrupted.
To correct this, you need to reset the list., e.g. like this:
select any file.
from the toolbar select "Actions (quick)"
Select the action type "Replace"
click on the button with the right-arrow and select "Reset field list" from the menu.
Cancel the action.
Hopefully, you see all fields again

Edit: no, you are right, resetting does not help. Sorry.

You can add an edit field for the tag field RELEASETIME into the Mp3tag tag panel.
See attached picture.



That seems to be working nicely.
I must say I wouldn't expect such a 'threshold' to make use of a standard id3v2.4 tag in MP3Tag, but that is probably saying more about my lack of understanding of the matter. (and your great program)